Reversing and speed-regulating mechanism for steam engines



July 15, 1930.

H. .w. Topo RBVERSING AND SPEED REGULATING MECHANISM FOR STEAM ENGINES Filed July 5, 1927 ZSheets-Sheet l INYENTOR ATTORNEY July 15, 1930. H. w. TODD REVERSING AND SPEED REGULATING MECHANISM FOR STEAM ENGINES Filed July 5, 1927 2 Sheets-Sheet 2 INVENTOR Horr I5 Hf 750M ATTORNEY 1 Patented July 15, 1930 fnonms ws'ronngor nnmvmrenn'oizmnoma j 'REVEBSING' AND srnnnmneurmmeMECHAN SM FOR :mmemmms] I application fil d-Jul 's,

1927. ..S.eria1 m5. 203,432.

i invention relates to reversing and speed i The valve chest l7 formedintegrally with thecylinder .6 comprises achamberrl8 having regulating mechanism for steam enginesiand more particularly to an improvement in means of controlling volume of flow and-distribution of ste amtov the engine for reversing [direction or varying the speed of operation.

:In accomplishingthis object I have provided improved details of structure, the preferred forms of wh'ich are illustrated in-the' accompanying drawings,wherein:

Fig. 1 isaplan View of a single cylinder, horizontal steam engine equipped with my improved reversing and speed regulating mechanism, apart of the cylinder and valve nected with the pin '13-of'the mainacrank {shafts being broken away "for better illustration.

Fig.i2. is=a vertical sectionon'the line 2. 2, Fi .1. be

I n j Fig.3 is-an enlarged detail ,perspective view of the reversing and vspeed-regulating mechanism. is v.

I Fig. 4; is'a.transverseverticalksection on the line 4 -4, Fig. s f Fig. Sis a vertical section-onthe li'n'e "5-5, i v Fig; 6 is'a vertical sectionon the line 66, vFig.1. p

Referring morein detail tothe drawings: l designates thebodycasting of a steam engine of horizontal type comprising a base 2, crank shaft bearings 33, a cross head guide 4, a cylinder headwflangee and valve 'rojd :guides 6 all of conventional design. "=7 desig-v nates a cylinder having a flange8 attached to the head flange-5 on the bodycasting by bolts, to mount. the casting. I p v p Located within the cylinder chamber 10 is apiston llhaving a rod 12 extended through theinner cylinder head and operatively conshaft 14 through. aconnecting' 11561115. The bearings 3- -3 are of theusual'split construction and thenrankshaift' 14; provided .vvithea :cylindenrigidly on thebod-y communication with opposite ends ofjthe' cylinder chamber 10 through'the ports lQ-and land is: provided with -;the usual intermediate exhaust, port 21 Located withinthe valve chestis a slidevalve 22 adapted-for selective- 1 1y "communicating the steam chamber with either end ofthe cylinder chamber through aport19 or 20 and simultaneously communieatingthe opposite end of the'cylinder chamber with exhaust port :21 through the opposite intake port 19 or 20in accordance with'cornmonpractice. -v The steam valve 22' islp'rovided witha rod 23 which extends .rearwardly through a stuf- ;fing box. 24 intdand through theguide 6 where it: is'provided with. an angular section 25 for properly guiding the {rod during its reciprocatory movement. At. its rear end the l with the crank shaft through the improved gearing mechanism which I will now describe.

, 27 designates a bracket comprising an'inside, vertical plate 28 attached adjacent the crank s'ha'ft',-to the side ofthe' engine casting, preferably'byhbolts 29', and provided near-its lower edge with an outwardly directed shelf ,30 having a standard 31 extending parallel with and in spaced relation to the attaching plate 28. An outsideplate 32Ilying parallel with and in spaced relation to'the standard 31 is attached to the shelf 30,preferably by the" bolts 33. Theinside plate 28 and the standard 31 are provided with paired bearings 34: and 35,'androtatable in said bearings are the extended hub portions 36 and 37of a gear wheel 38 which meshes with a gear wheel 39 fixed on the crank shaft 1.4.

The --gear wheel ,38 "and its "extend portions'36 and 37 are providediwith aniin teriorspiral groove 40 for the 'spiralled rib 421015 a contained sleeve43 which constitutes gthef fsleevej of. an, elongated worm gear wheel;

Extending through and keyed to the sleeve or worm gear wheel 43 by splines 44 is a secondary shaft 45, having a reduced end 46 j ournaled in the bearing 47 on the upper end of the inside plate 28 of the bracket 27, and forming a shoulder 48 for abutment against the inner face of the bearing to limit longitudinal movement of the secondary shaft.

Fixed to the reduced portion 46 of the shaft is a crank 49 which is adapted for bearing laterally against the face of the adjacent bearing 47 to limit longitudinal movement of the shaft in theopposite direction and provided with an eccentric pin 50 on which the head 51 of the valve connecting rod 26 is pivotally mounted.

Fixed to the outer end of the sleeve or elongated worm gear wheel 43, preferably by a set screw 52, is a stop collar 53. Fixed on the opposite end of said sleeve or elongated worm gear wheel, preferably by 'a set screw 54, is a collar 55 having an annular, peripheral groove 56 receiving theclutch segments 57 having studs 57 projecting through openings 58 of a yoke 59, of a lever 60 which is pivotally mounted on a pin 61 carried by the ears 62 that project inwardly from the inside bracket plate 28 the end of the lever opposite the yoke being provided with a handle 63 whereby the lever may be shifted on its pivotal mounting to shift the collar 55. The collars 53 and 55 may be spaced to provide for movement of the Worm gear wheel within its gear wheel 38 from one given extreme to the other before interruption of movement by contact with either of the collars at a relative end of the bearings 34 and 35, or the collars may be set to interrupt movement of the Wheel at intermediate points.

Assuming the parts to constructed and assembled as described, and further assuming, for illustration, that adjustments of the valve are made with the crank on dead center, the operation is as follows:

For normal forward, operationof the engine the valve controlling crank isset perpendicularly above its shaft with the crank slightly below its rearward dead center. As the crank shafts revolve, the valve regulating crank moves forwardly in front of the main crank, opening the forward valve port to admit steam to the rear portion of the piston chamber to drive the piston forwardly and rotate the crank clockwise (Fig. 1), With the valve regulatingcrank set perpendicularly below its shaft, and the main crank slightly above dead center, the valve crank will lead the main crank one reverse operation.

Position of the valve regulating crank in line with the main crankwould neutralize the valve operation and prevent admission of steam toeither end of the piston chamber, while any adjustment intermediate the neutral position and either extreme would serve to advance or retard admission of steam to the cylinder and correspondingly'vary the power and speed of the engine.

In order to effect adjustment of the valve regulating crank for either forward or reverse operation of the engine and for inter mediate speeds, the elongated worm gear is shifted longitudinally by means of the operating lever, the toothed connection between the elongated sleeve 42 and the gear wheel 38 effecting rotation of the sleeve and the secondary shaft because of the locked engagement of the gear wheel 38 with the gear wheel on the main crank shaft with which it is in mesh, and rotation of the secondary sha-ft shifting the valve regulating crank to vary its angularity relative to the main crank shaft. The stop collarson the elongated worm gear or toothed sleeve may be so spaced that when the gear or sleeve is at one limit of its movement, the valve regulating crank is set for maximum forward operation of the engine and when at the other ,limit of its movement, for maximum reverse travel.

Intermediate speeds may be secured by adjustment ofthe collars on the sleeve at points intermediate the extremes so that when the sleeve is shifted in one direction a collar will engage a hub of the worm gear wheel before its extreme is reached-and thereby limit angularity of the valvecrank and resultant opening of the valveport.

It is apparent therefore that the worm gear mechanism may be set to provide desired speed of operation and that when a setting is made the operation for forward or reverse travel may be controlled by shifting of the control lever to contact one or the other of the collars with the hub of the inner gear wheel and limit shift of the sleeve in direction of thrust.

7 Other changes to meet requirements of different engine structure may be made without departing from the spirit of my invention.

What I claim and desire to secure by Letters Patent is:

l. A reversing and speed regulating device for steam engines including in combination with a crank shaft, a steam valve and a valve rod, a secondary shaft, a crank on the secondary shaft connected with the valve rod. a sleeve splined on the secondary shaft and slidable longitudinally thereon, the sleeve having external threads, a drive wheel threaded on said sleeve, the sleeve being movable through the drive wheel, means driving the drive wheel from the crank shaft, and means for shiftingthe sleeve longitudinally to effect rotation of the sleeve through its threaded connection with the relatively stationary drive wheel for varying angularrod, a secondary shaft, acrank'o'n the second; ary shaft connected With the valve rod, a sleeve splined on the secondary shaft having" external threads and longitudinally slidable on the shaft, a drivewheel threaded on said sleeve and rotating the same, means engaged v Withthe drive Wheel for operating the same I from the crank shaft, a collar fixed on said 1 7i I sleeve and a shifting lever, connected with 5 said collar for shifting the sleeve longitudinally for effecting variation in angularity" l of the valve rod crank.

In testimony whereof I affix my signature. I

I HORRIS W; TODD. 

